If you think they may have been altered at some time to fit different flywheels or you are using different flywheels, slip the crank assembly one case half and check the clearance with a feeler gauge. I'm not aware of a clearance spec I just fit them as close as I can without dragging. Dusty

Jib, 45 scrapers and K scrapers are the same. All H-Ds only have one, it is continuous across the crankcase. K models do not have baffles because ring technology made them redundant. The K top end is an easy deal, relocate one hole for the bases, swap the tappet guides for angled ones ( moldthread's are really nice, but so are Kurt's) , create a feed for the skirt oilers. No case mods are necessary to scrapers, even if you use aftermarket flywheels for more stroke. And 45s work just fine without baffles using modern oil rings.Robbie

thanks guys , 45s have that little 'scraper' at the top of the cases as well ,do k's have that too.

robbie have welded up the cases were the stud needs moving (about 3 years ago ) and have drilled n taped the cases for feed and provided a feed drilling to the barrel bases . using either a 45 pump modded as per jims improvements or a modified return pump with spacer plate by george greer.

Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

If you're going through the exercise of bringing oil pressure to the cylinder base, IMHO, I would continue the design process by abandoning the skirt oiler in the K cylinder in favor of a piston squirter who's oil stream was directed to the underside of the piston crown (rather than across the bore at the piston skirt). See Frankenstein's site for pictures of his version of a piston crown oiler.

Having the oil stream impinge directly on the under side of the piston crown would be significantly more effective at cooling the engine than simply having the oil stream squirt across the bottom of the bore at the piston skirt. After all, the crown of the piston is where combustion heat is absorbed and the area you are desperately trying to cool, not the piston skirt. If you hit the crown with the oil stream, this would likely improve the skirt cooling anyway, since the oil stream hitting the crown will be splashing or draining over the skirt as it returns to the bottom end.

If you undertake such a project I'd stick with a ~ 0.040" dia orifice in the terminal end of the squirter (same size as in the stock K barrel), since this will flow lots of oil if pressurized properly.

i had thought of that and agree Dr dicks ,squirters are superb , thoutgh i wonder if a 45 really needs them ,i dont think they would get hot enoutgh . unlike a bt flattie which purportedly does , regards jib

Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Regarding operating temp of a 45, I think if you ride it conservatively you'd be fine with the stock set-up, but if you want to "ride it like you stole it" or do some higher speed cruising into a stiff head-wind, or on long grades, I could definitely envision temperature issues arising.

The most recent issue of the AMCA magazine (spring 2012 Vol. 52 No. 1) had a brief technical article on pistons in it, and specifically pistons in Henderson fours. There was mention made in the article of piston squirters, and the benefit they provide. There was also a picture of new Ross pistons, run in Henderson fours with and without piston squirters, and as always, the squirted piston (right) looked like it was right out of the box, and the non-squirted piston (left) looked like it had been on the BBQ with the burgers.

I can't say from personal experience, as I've never had the good fortune to own a Henderson, but my Pop, a man who loved his Hendersons said they ran very hot. He felt this was because the inline four didn't cool the cylinders well in SoCal desert. He switched over to early ELs when they came out, but he always spoke lovingly about the smoothness and solidity of his much loved Hendersons. I can see where oil jets would cure this problem.